This section provides basic introduction to network, what is computer networkng, ethernet overview, lan/wan technology, internet communication system and basic lan concepts. The term “network” in computing system means two or more computers connected each other to form a network and networking means two or more computers connected with each other and sharing data and resources. Today every business in the world from banking to airlines offices, corporate organizations, postal services, universities and a even a home where there are two or more computers, need a network to communicate with other people.

With the passage of time, the network technology has adopted many new standards and many inventions in this industry are on their way to provide the maximum advantages according to the needs of every business.

There are many standards and technologies that are involved to form a computer network and based on these standards, there are several protocols, topologies, cables and devices are also the part of a computer network. I will provide a general overview of the basic networking technology, standards and devices.

Protocols are the agreed upon ways, communication language and a set of rules which both the networking computers understand and communicate with each other. Protocols by default come with the operating systems and computer use them to communicate with each other. The most popular protocol on the internet and LAN is the TCP/IP protocol. TCP/IP basically a suite of the protocols, such as TCP, IP, HTTP, DNS, FTP, PPTP, DHCP, HTTPS, LDAP and many other communication protocols.

Ethernet is a LAN standard for the network communication. Ethernet was developed by the Xerox system and it comes in the IEEE (Institute of Electrical and Electronics Engineers) standards of 802.3. Ethernet work with CSMA/CD technology and Hub, switch, twisted pair cables, connectors come in the Ethernet technology. Today fast Ethernet such as Gigabyte Ethernet technology work as the backbone for many LAN and WAN technologies and it works at the speed of 1Mb/Sec.

Cables are the integral part of a network especially a local area network. There are different types of cables that are used in the network communication system. Such as twisted pair cables UTP/STP, coaxial cable, copper wire and fiber optic cables. In the LAN technology, the most popular cable is unshielded twisted pair and twisted pair cable.

A computer network requires a complete, secure, safe and reliable environment to perform well. There are several network security threats that can damage a whole network. To make your network secure, you should have a updated antivirus program, updated operating system, email monitoring system and many other security measures. Only authorized persons should be allowed to access your network resources. Your gateway computer should be well secure because it is directly exposed to the internet.

There are several network devices that are the part of a compute network such as hub, switch, router, NIC adapter, gateway device, modems, wireless access points and many other devices. Every device performs a different function for example a hub is central device and every computer in a network is directly connected with the hub or switch. A router is used to connect the two different logically and physically different networks in a LAN or WAN. The communication on the internet is based on the routers.

OSI model layer are the logical layers which are designed to understand the complete communication system. There are several logical layers which were developed by the ISO (International standardization organization). Every layer performs different function and data in a network travels at every layer. The seven layers are 1. Application, 2. Presentation, Session, Transport, Network, Data link and Physical. You can remember the sequence of the layers by this sentence.
“All people seems to need data processing”

There are two basic types of a computer network peer to peer network and client/server network. In a peer to peer network, there is no central serve and every computer in the network is a part of the same workgroup. No centralized management and control is present in this type of networking. In the client/server networking model, a centralized network server or a domain controller is present and every computer in a network is dependent on the server for the services such as logon access, files, printer, internet access, distributed applications and many other resources. If the server stops working, the communication in a network stops so the server availability and access is very important in client/server communication model. A network can also be categorized in a LAN, MAN, CAN, HANs, SAN and WAN.

A network in a room or a building of a office known as a LAN (Local area network) and a network between the two buildings of the same city known as MAN (metropolitan area network) a network in a university is known as (CAN) and a network between the two countries is know as WAN (wide area network). There are different physical and logical topologies of a network. The basic network topologies are star, bus, mesh, tree, ring and hybrid. Topology means the physical design or layout of a network. The most common used topology is a start topology in which a centralized device known as a hub or switch is used and all the other computers are directly connected with the hub.

Today every business in the world, need a private network to share data and provide a communication system among the employees of an organization. Big the network of a company more administration is required to manage the day to day problems and troubleshooting. A person who is dedicated to deal with the network administration is known as a network administrator. Different companies like Cisco Systems, Microsoft, Comptia, ISC2 and many others have originated many certification programs such as MCSE, CCNA, CCNP, MCSA, A+, CISSP, Server+, and Security+ to make the network administrators more professional, powerful, knowledgeable and resourceful. Internet is a network of networks and a large number of ISPs around the world, online dedicated servers and even our home computers, when connected with the local ISPs, are the part of the internet. Internet is a broadest shape of a network communication system and the router is the key device that involves in the internet communication system.